Portable navigation devices, such as the GO™ and ONE™ devices from TomTom International B.V., are increasingly popular for in-vehicle navigation. Embedded in-vehicle navigation systems, by contrast, are falling in overall market share. There are several reasons for this. First, embedded in-vehicle navigation systems are significantly more costly for the end-user. Secondly, they generally do not include the latest technology: when designing a highly complex product such as a motor vehicle, the design of the in-vehicle navigation systems has to be frozen typically 3 years before the vehicle is launched. This is to give enough time for the complex integration and testing that needs to be done for a system embedded into a vehicle, and the long lead times of setting up manufacturing assembly lines for motor vehicles. So an expensive motor vehicle, 5 years after launch, may be offered with an embedded navigation system that is at least 8 years old, and possibly older. By contrast, portable navigation devices tend to be updated at least yearly: new models may have more sensitive GPS chipsets, better maps, faster processors, as well as improved functionality such as real time traffic data. And they are generally far cheaper than embedded navigation systems.
Portable navigation devices have in the past generally had no ability to interface with factory installed equipment or systems in the vehicle, such as the embedded factory-fitted vehicle stereo. One limited exception is that it is possible to connect the TomTom GO wirelessly to a Bluetooth™ interface box that is installed into a vehicle, behind the dashboard, as an after-market accessory (i.e. it is not factory fitted); the interface box is then connected by wires by a skilled installer to the in-vehicle stereo. One interface product that does this is the TomTom Car Connect™. The TomTom Car Connect system, released on late 2006 and hence not necessarily relevant prior art, whilst allowing the PND to wirelessly connect to an interface box, still required the interface box itself to be professionally installed behind the vehicle dashboard. However, take up of this is likely to be quite limited because most ordinary users do not want the trouble or cost of professionally installing a dedicated interface box behind their vehicle dashboard for their GO portable navigation device.
Another solution has been used in the Toyota Aygo; this motor vehicle required the GO dock to be permanently hard wired to an interface box, in turn hard wired to the radio/speakers of the vehicle. This was done as part of the factory build. The user could then simply mount the GO onto the dock whenever needed. But again, the cost and trouble of installing a dedicated interface box is considerable. A permanently installed dock for the portable navigation device can also require adaptation of the dashboard.
It is however known to provide a wireless interface connected to the in-vehicle stereo to enable mobile telephones to be used in a hands-free mode. The Parrot™ Bluetooth handsfree vehicle kits are well known examples. But, as with the TomTom Car Connect™ device, these kits require careful installation, which limits their appeal.
Reference may be made to WO 00/72463, which discloses a wireless communication system for use in a vehicle. It enables notebooks computers, cellphones, and pagers to communicate over a short range wireless network with factory-installed subsystems in the vehicle, such as an on-board navigation system. But, it does not describe enabling a portable navigation device to communicate with the factory installed subsystems at all. The same can be said of WO 2005/024781; this describes connecting various wireless enabled devices, such as mobile phones, to a voice recognition engine. Although it does describe connecting a GPS device to the voice recognition engine, the GPS device is not described as having any kind of wireless interface; the reasonable inference is that it is an embedded navigation device and not a portable navigation device.
Reference may also be made to US 2006/0140210: this describes an automotive data bus that enables devices such as cell phones, garage door openers etc. to be wirelessly connected to an in-vehicle data bus and hence to the factory-fitted items that are connected to that data bus, such as the CD player, multi-function steering wheel etc. It does suggest that an external GPS receiver can be connected to the data bus, but adds that one of the existing devices on the data bus that the GPS receiver can connect with is a navigation system. This disclosure hence appears to contemplate being able to enhance the performance of a factory-fitted, embedded navigation system by connecting it to an external GPS receiver over the data bus. Again, this document does not deal with interfacing a portable navigation device to the factory fitted systems of a motor vehicle.
In US 2002/0140548, an in-vehicle wireless network is described; the GPS navigation system is not a portable navigation device but an embedded device built into the trunk. US 2004/0133319 describes how a portable digital assistant with no navigation capability can be used to interface with systems in a vehicle, and again does not relate to a portable navigation device. US 2003/0212485 also deals with enabling a portable computing device, which is explicitly distinguished from autonomous route guidance systems like portable navigation devices, to interface with vehicle systems. In WO00/74019, a PDA is linked to an embedded navigation system.
US2003/0114980 discloses a method and system for a wireless interface to the electronics of an automotive vehicle for a remote application in the vehicle or within communication range of the vehicle. The remote application may be a navigation system using vehicle motion sensor data to provide or improve a navigation solution for the vehicle. In an alternative embodiment, the remote application is diagnostic software running on a handheld computer that evaluates vehicle systems in a diagnostics procedure. This document also describes a system for navigating a vehicle including a vehicle sensor connected to a vehicle bus connected to a gateway node, and a processor in the vehicle communicating wirelessly with the gateway node and connected to a vehicle positioning system. The sensor measures a value and then transmits the value over the vehicle bus to the gateway node using a network protocol. The gateway node then wirelessly transmits the value to the processor using a wireless communication protocol. The processor receives an initial position from the positioning device and calculates a current position using a former position, the initial position, and the sensor value. A protocol translation device is disclosed that may include two different protocols and an intermediate, network-independent protocol. In one embodiment of the invention, an emerging worldwide standard, Bluetooth, created by the Wireless Personal Area Network (WPAN) Working Group (IEEE 802.15), provides a wireless interface to the electronics in the vehicle via a Controller Area Network (CAN). CAN is an international standard documented in ISO 11898 (for high-speed applications) and ISO 11519 (for lower-speed applications). A remote application, such as a navigation system or a hand-held computer running navigation software, can connect to this interface via a host inside the vehicle or within communication range of the vehicle.
Additionally, U.S. patent application Ser. No. 09/687,181 describes a system for providing short-range wireless access to data on vehicle buses and data in the memory of electronic control units (ECUs) via a wireless link. This application discusses interfacing a CAN (Controller Area Network) protocol on the vehicle bus communicating with a gateway node and Bluetooth hardware set.